Lanthanide
Dysprosium is a chemical element; it has symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is 164Dy.
Dysprosium was first identified in 1886 by Paul Émile Lecoq de Boisbaudran, but it was not isolated in pure form until the development of ion-exchange techniques in the 1950s. Dysprosium is used to produce neodymium-iron-boron (NdFeB) magnets, which are crucial for electric vehicle motors and the efficient operation of wind turbines. It is used for its high thermal neutron absorption cross-section in making control rods in nuclear reactors, for its high magnetic susceptibility (χv ≈ 5.44×10−3) in data-storage applications, and as a component of Terfenol-D (a magnetostrictive material). Soluble dysprosium salts are mildly toxic, while the insoluble salts are considered non-toxic.
In 1878, erbium ores were found to contain the oxides of holmium and thulium. French chemist Paul Émile Lecoq de Boisbaudran, while working with holmium oxide, separated dysprosium oxide from it in Paris in 1886. His procedure for isolating the dysprosium involved dissolving dysprosium oxide in acid, then adding ammonia to precipitate the hydroxide. He was only able to isolate dysprosium from its oxide after more than 30 attempts at his procedure. On succeeding, he named the element dysprosium from the Greek dysprositos (δυσπρόσιτος), meaning "hard to get". The element was not isolated in relatively pure form until after the development of ion exchange techniques by Frank Spedding at Iowa State University in the early 1950s.
Due to its role in permanent magnets used for wind turbines, it has been argued that dysprosium will be one of the main objects of geopolitical competition in a world running on renewable energy. But this perspective has been criticised for failing to recognise that most wind turbines do not use permanent magnets and for underestimating the power of economic incentives for expanded production.
In 2011, a Bose-Einstein condensate of Dy atoms was obtained for the first time.
In 2021, Dy was turned into a 2-dimensional supersolid quantum gas.
Dysprosium is a rare-earth element and has a metallic, bright silver luster. It is soft and can be machined without sparking if overheating is avoided. Dysprosium's physical characteristics can be greatly affected by even small amounts of impurities.
Dysprosium and holmium have the highest magnetic strengths of the elements, especially at low temperatures. Dysprosium has a simple ferromagnetic ordering at temperatures below its Curie temperature of 90.5 K (−182.7 °C), at which point it undergoes a first-order phase transition from the orthorhombic crystal structure to hexagonal close-packed (hcp). It then has a helical antiferromagnetic state, in which all of the atomic magnetic moments in a particular basal plane layer are parallel and oriented at a fixed angle to the moments of adjacent layers. This unusual antiferromagnetism transforms into a disordered (paramagnetic) state at 179 K (−94 °C). It transforms from the hcp phase to the body-centered cubic phase at 1,654 K (1,381 °C).
Dysprosium metal retains its luster in dry air, but it will tarnish slowly in moist air. It burns readily to form dysprosium(III) oxide:
4 Dy + 3 O2 → 2 Dy2O3
Dysprosium is quite electropositive and reacts slowly with cold water (and quickly with hot water) to form dysprosium hydroxide:
2 Dy (s) + 6 H2O (l) → 2 Dy(OH)3 (aq) + 3 H2 (g)
Dysprosium hydroxide decomposes to form DyO(OH) at elevated temperatures, which then decomposes again to dysprosium(III) oxide. …
While dysprosium is never encountered as a free element, it is found in many minerals, including xenotime, fergusonite, gadolinite, euxenite, polycrase, blomstrandine, monazite and bastnäsite, often with erbium and holmium or other rare earth elements. No dysprosium-dominant mineral (that is, with dysprosium prevailing over other rare earths in the composition) has yet been found.
In the high-yttrium version of these, dysprosium happens to be the most abundant of the heavy lanthanides, comprising up to 7–8% of the concentrate (as compared to about 65% for yttrium). The concentration of Dy in the Earth's crust is about 5.2 mg/kg and in sea water 0.9 ng/L.
Dysprosium is used, in conjunction with vanadium and other elements, in making laser materials and commercial lighting. Because of dysprosium's high thermal-neutron absorption cross-section, dysprosium-oxide–nickel cermets are used in neutron-absorbing control rods in nuclear reactors. Dysprosium–cadmium chalcogenides are sources of infrared radiation, which is useful for studying chemical reactions. Because dysprosium and its compounds are highly susceptible to magnetization, they are employed in various data-storage applications, such as in hard disks. Dysprosium is increasingly in demand for the permanent magnets used in electric-car motors and wind-turbine generators.
Neodymium–iron–boron magnets can have up to 6% of the neodymium substituted by dysprosium to raise the coercivity for demanding applications, such as drive motors for electric vehicles and generators for wind turbines. This substitution would require up to 100 grams of dysprosium per electric car produced. Based on Toyota's projected 2 million units per year, the use of dysprosium in applications such as this would quickly exhaust its available supply. The dysprosium substitution may also be useful in other applications because it improves the corrosion resistance of the magnets.
Dysprosium is one of the components of Terfenol-D, along with iron and terbium. …
Naturally occurring dysprosium is composed of seven isotopes: 156Dy, 158Dy, 160Dy, 161Dy, 162Dy, 163Dy, and 164Dy. These are all considered stable, although only the last two are theoretically stable: the others can theoretically undergo alpha decay. Of the naturally occurring isotopes, 164Dy is the most abundant at 28%, followed by 162Dy at 26%; the rarest is 156Dy at 0.06%. Dysprosium is the heaviest element to have isotopes that are theoretically stable rather than only observationally stable isotopes that are predicted to be radioactive.
Twenty-nine radioisotopes have been synthesized, ranging in atomic mass from 138 to 173. The most stable of these is 154Dy, with a half-life of 1.40×106 years, followed by 159Dy with a half-life of 144.4 days. As a general rule, isotopes that are lighter than the stable isotopes tend to decay primarily by β+ decay, though 154Dy decays by alpha emission and 152Dy and 159Dy only by electron capture, while those that are heavier tend to decay by β− decay. Dysprosium also has at least 11 metastable isomers, ranging in atomic mass from 140 to 165. The most stable of these is 165mDy, which has a half-life of 1.257 minutes.
Like many powders, dysprosium powder may present an explosion hazard when mixed with air and when an ignition source is present. Thin foils of the substance can also be ignited by sparks or by static electricity. Dysprosium fires cannot be extinguished with water. It can react with water to produce flammable hydrogen gas. Dysprosium chloride fires can be extinguished with water. Dysprosium fluoride and dysprosium oxide are non-flammable. Dysprosium nitrate, Dy(NO3)3, is a strong oxidizing agent and readily ignites on contact with organic substances.
Soluble dysprosium salts, such as dysprosium chloride and dysprosium nitrate are mildly toxic when ingested. Based on the toxicity of dysprosium chloride to mice, it is estimated that the ingestion of 500 grams or more could be fatal to a human (cf. lethal dose of 300 grams of common table salt for a 100 kilogram human). The insoluble salts are non-toxic.